The Kazaa Overlay
The KaZaA Overlay: A Measurement Study
Jian Liang
Department of Computer and
Information Science,
Polytechnic University,
Brooklyn, NY, USA 11201
Email: jliang@cis.poly.edu
Rakesh Kumar
Department of Electrical and
Computer Engineering,
Polytechnic University,
Brooklyn, NY, USA 11201
Email: rkumar04@utopia.poly.edu
Keith W. Ross
Department of Computer and
Information Science,
Polytechnic University,
Brooklyn, NY, USA 11201
Email: ross@poly.edu
September 15, 2004
Abstract
Both in terms of number of participating users and in tra±c volume, KaZaA is one of the most important applications in the Internet today. Nevertheless, because
KaZaA is proprietary and uses encryption, little is understood about KaZaA's overlay structure and dynamics, its messaging protocol, and its index manage- ment. We have built two measurement apparatus - the KaZaA Sni±ng Platform and the KaZaA Probing Tool - to unravel many of the mysteries behind KaZaA.
We deploy the apparatus to study KaZaA's overlay structure and dynamics, its neighbor selection, its use of dynamic port numbers to circumvent ¯rewalls, and its index management. Although this study does not fully solve the KaZaA puzzle, it nevertheless leads to a coherent description of KaZaA and its overlay. Further- more, we leverage the measurement results to set forth a number of key principles for the design of a successful unstructured P2P overlay. The measurement results and resulting design principles in this paper should be useful for future architects of P2P overlay networks as well as for engineers managing ISPs.
1
1 Introduction
On a typical day, KaZaA has more than 3 million active users sharing over 5,000 terabytes of content. On the University of Washington campus network in June 2002,
KaZaA consumed approximately 37% of all TCP tra±c, which was more than twice the Web tra±c on the same campus at the same time [8]. With over 3 million satis¯ed users, KaZaA is signi¯cantly more popular
Jian Liang
Department of Computer and
Information Science,
Polytechnic University,
Brooklyn, NY, USA 11201
Email: jliang@cis.poly.edu
Rakesh Kumar
Department of Electrical and
Computer Engineering,
Polytechnic University,
Brooklyn, NY, USA 11201
Email: rkumar04@utopia.poly.edu
Keith W. Ross
Department of Computer and
Information Science,
Polytechnic University,
Brooklyn, NY, USA 11201
Email: ross@poly.edu
September 15, 2004
Abstract
Both in terms of number of participating users and in tra±c volume, KaZaA is one of the most important applications in the Internet today. Nevertheless, because
KaZaA is proprietary and uses encryption, little is understood about KaZaA's overlay structure and dynamics, its messaging protocol, and its index manage- ment. We have built two measurement apparatus - the KaZaA Sni±ng Platform and the KaZaA Probing Tool - to unravel many of the mysteries behind KaZaA.
We deploy the apparatus to study KaZaA's overlay structure and dynamics, its neighbor selection, its use of dynamic port numbers to circumvent ¯rewalls, and its index management. Although this study does not fully solve the KaZaA puzzle, it nevertheless leads to a coherent description of KaZaA and its overlay. Further- more, we leverage the measurement results to set forth a number of key principles for the design of a successful unstructured P2P overlay. The measurement results and resulting design principles in this paper should be useful for future architects of P2P overlay networks as well as for engineers managing ISPs.
1
1 Introduction
On a typical day, KaZaA has more than 3 million active users sharing over 5,000 terabytes of content. On the University of Washington campus network in June 2002,
KaZaA consumed approximately 37% of all TCP tra±c, which was more than twice the Web tra±c on the same campus at the same time [8]. With over 3 million satis¯ed users, KaZaA is signi¯cantly more popular
References: November, 2003. [17] J. Kurose, K.W. Ross, Computer Networking: A Top-Down Approach Featuring the Internet," Addison-Wesley, 2005. [19] J. Liang, R. Kumar, Y. Xi, K.W. Ross, Pollution in P2P File Sharing Systems," submitted, 2004. Supercomputing, New York City, NY, USA, June, 2002. Internet Computing Journal, vol. 6, no. 1, 2002. Analysis of Internet Content Delivery Systems," Proceedings of the 5th Symposium on Operating Systems Design and Implementation (OSDI 2002), Boston, MA, USA,